Black Seed (Nigella Sativa) in Islamic and Other Traditions: What Research Shows
Black seed (Nigella sativa) has a long place in Islamic and South Asian traditions; trials suggest small blood pressure and blood sugar changes, with allergy risks and unanswered safety questions.
Content last updated . This page has not been medically reviewed.
What it is
Black seed, also called black cumin or Nigella sativa, is a plant in the buttercup family (Ranunculaceae). It grows across the eastern Mediterranean, northern Africa, the Indian subcontinent and Southwest Asia, and is a familiar cooking seed. [1] Some people search for it by its Arabic name, habbatus sauda. This page covers the traditions around it and what trials have measured. It is information only. For general herb safety see herb safety and interactions.In Islamic and other traditions
Black seed has long been described in several traditional systems, including Unani, Ayurveda, Tibb and Siddha, and across Arab nations, Asia, Africa and Europe. [1] Black cumin was reportedly found in the tomb of Tutankhamun. [1]In Islamic tradition, a review of the seed reports a saying (hadith) that black seed holds a cure for every disease except death, and calls it part of Prophetic medicine. [2] For many Muslims this carries spiritual meaning that research cannot measure. The same review also notes toxicity of the seed's volatile oils at larger doses. [2] More on the tradition is in Prophetic medicine. Historical use is a reason to study a plant, not proof that it works or is safe (historical use vs clinical evidence).
What research shows
Most human studies test black seed as a supplement (seed, powder or oil) in adults with metabolic conditions. Important limit: trials used different products and amounts, and ran from 1 to 48 weeks. [3]| Question | What the source found | Evidence label |
|---|---|---|
| Blood pressure | A meta-analysis of randomized trials found average falls of about 3.1 mmHg (systolic) and 2.7 mmHg (diastolic), but results varied a lot between trials (I-squared 84.7% and 97.3%). [4] | Promising but limited |
| Blood sugar and cholesterol in prediabetes or type 2 diabetes | A meta-analysis of 11 trials found changes in fasting glucose, HbA1c, total cholesterol and LDL cholesterol. [5] | Promising but limited |
| Overall heart and metabolic risk factors | A 2025 review of 82 studies with 5,026 people found improvements in many risk markers and called black seed a promising adjunct therapy. [3] | Promising but limited |
| Liver and kidney markers | A meta-analysis found lower ALP and BUN, but higher daily amounts raised BUN, and the authors called for larger, longer, higher-quality studies. [6] | Insufficient evidence on safety |
| Cancer, infection, asthma and many other uses | A 2021 review says black cumin and its main compound, thymoquinone, are still far from clinical application, and calls for human studies. [1] | Preclinical |
A small average change in blood pressure is not a treatment on its own. Do not use black seed instead of prescribed medicine. See understanding evidence.
Who should take extra care
People with allergies to plants, liver or kidney disease, diabetes or low blood pressure, people on blood pressure, diabetes, seizure or transplant medicines, and anyone pregnant. Seek medical care first for chest pain, severe symptoms, or uncontrolled blood pressure or sugar.Frequently asked questions
Is black seed the same as black cumin?
Yes. Black seed and black cumin are common English names for Nigella sativa. [1]
Does black seed lower blood pressure?
A meta-analysis found average falls of about 3 mmHg, with large differences between trials. [4] It is not a replacement for blood pressure medicine.
Can black seed cure diabetes or cancer?
No. Trials of type 2 diabetes measured changes in lab markers, not cures. [5] For cancer and most other uses, the research is still early. [1]
Is black seed oil safe to put on skin?
Allergic contact dermatitis from the oil has been reported in case reports. [7] Test with a clinician's advice and stop if a rash appears.
Can I take black seed with my medicines?
Ask a pharmacist first. Interaction data are mostly from animals, and black seed may add to the effects of blood pressure and diabetes medicines. [1]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety, product quality and interactions
- Allergy and skin reactions. Case reports describe allergic contact dermatitis, including a study that identified thymoquinone as the allergen with cross-reactivity to another chemical, and a bullous (blistering) drug eruption after the oil was used. [7][8] Stop and seek care for rash, swelling or breathing trouble.
- Toxicity. A narrative review of animal studies found that high doses of fixed oil can be slightly toxic in chronic studies, and concluded that more detailed studies are needed to draw a firm conclusion on safety. [9]
- Medicines. Interaction studies are mostly in animals. In those models thymoquinone changed levels of drugs including phenytoin and sildenafil, and had additive effects on blood sugar with one diabetes drug. [1] Because black seed lowered blood pressure and glucose in trials, ask your prescriber or pharmacist if you take medicines for those. See how interactions work.
- Liver and kidney disease. Some trial markers rose at higher amounts. [6] Ask your clinician; see liver safety.
- Pregnancy and breastfeeding. In rats given thymoquinone by injection at higher doses, harm to the pregnancy was seen, while a vaginal pessary form did not cause problems in rats. [1] Proper evidence not found for oral use in human pregnancy, so ask your midwife or doctor. See pregnancy and breastfeeding.
- Children. Proper evidence not found on safe amounts for children. We searched the reviews listed below. Ask a pediatrician.
- Product quality. Seeds, oil and capsules vary, and this guide gives no amounts. See product quality. Tell your surgical team about any supplement before surgery.
References
- Hannan MA, et al. Black cumin (Nigella sativa L.): a comprehensive review on phytochemistry, health benefits, molecular pharmacology, and safety. Nutrients 2021. Read 2026-10-22.
- Ijaz H, et al. Review: Nigella sativa (Prophetic Medicine): a review. Pak J Pharm Sci 2017. Read 2026-10-22.
- Jafari A, et al. Does Nigella sativa supplementation improve cardiovascular disease risk factors? A GRADE-assessed systematic review and dose-response meta-analysis of 82 randomized controlled trials. Pharmacol Res 2025. Read 2026-10-22.
- Kavyani Z, et al. Antihypertensive effects of Nigella sativa supplementation: an updated systematic review and meta-analysis of randomized controlled trials. Phytother Res 2023. Read 2026-10-22.
- Saadati S, et al. Nigella sativa supplementation improves cardiometabolic indicators in prediabetes and type 2 diabetes: a systematic review and meta-analysis. Front Nutr 2022. Read 2026-10-22.
- Razmpoosh E, et al. The effect of Nigella sativa on liver and kidney parameters: a systematic review and meta-analysis. Pharmacol Res 2020. Read 2026-10-22.
- Kurihara F, et al. Thymoquinone as a causative allergen in Nigella sativa oil contact dermatitis. Contact Dermatitis 2020 (title and record read). Read 2026-10-22.
- Bonhomme A, et al. Bullous drug eruption to Nigella sativa oil. J Eur Acad Dermatol Venereol 2017 (title and record read). Read 2026-10-22.
- Mashayekhi-Sardoo H, et al. Nigella sativa (black seed) safety: an overview. Asian Biomed 2020. Read 2026-10-22.